Connecticut and New England are experiencing a surge of activity aimed at constructing battery energy storage systems (BESS). BESS have been used in dedicated applications such as backup power for computer server installations for many years. Large conventional power plants have BESS in the event of a black-out of grid electrical power.
Large-scale applications of wind and solar generation need a method of storing intermittent, i.e., unreliable sources of energy. Electricity cannot be stored as electricity but must be converted to another form of energy. To match the grid’s technical requirements, lithium-ion batteries packed into enclosures resembling shipping containers were selected as the preferred alternative. The energy stored in just one container is capable of one megawatt of energy, equal to the combined output of about 30 Tesla Model S cars—equal to parking 150 Teslas for the Key Capture Energy project and 3,000 Teslas for the Broadleaf Solar project.
To manage the irregularity of wind and solar generation, Connecticut encouraged the development of 1,000 megawatts of BESS— 30,000 Teslas. This unleashed a stampede. In addition to “native” demand, developers with sites in Connecticut and good transmission access sought contracts with Massachusetts.
The Granby sites are close to the Eversource transmission line that developers covet to send power north. It crosses Route 20 in East Granby next to the rail trail. Recent upgraded capacity increased the line’s voltage to 345 kilovolts. It connects the North Bloomfield substation to Agawam with connections to Southwick and the Berkshires. Transmission line work is paid for by the “ratepayer”. Eversource can increase transmission tariffs after approval from regulatory control authorities to recover construction and financing costs plus net a profit.
Based on ISO New England (ISO NE) data, multiple battery projects are seeking approval to access the 345 kV transmission line, including large projects in Bloomfield, Granby, East Granby, Suffield and Agawam. Broadleaf Solar has stated that power generated in Granby will go to Massachusetts and Rhode Island.
The proposed BESS projects are unequally located relative to each county. A review and analysis of electric interconnection requests submitted to ISO-NE, 72 percent or 4,717 megawatts of projects are requesting tie-ins in Hartford, New Haven and New London counties. Fairfield and Litchfield combined only equal 10 percent or 653 megawatts. Middlesex county is at 6.4 percent and 41 megawatts.
Compare that to Connecticut’s peak load demand of about 6,500 megawatts. The developers in Hartford County will fight to obtain connection rights on two 345 kilovolt lines, on both sides of the Connecticut River that are major conduits for feeding power to Massachusetts.
Granby currently faces the development of two BESS projects by different developers. Broadleaf Solar has an interconnection request in to ISO-NE to add 100 megawatts of BESS to its planned 100 megawatts of solar. No documents have been submitted to the Connecticut Siting Council (CSC) for certification. The second project, Key Capture Energy, is on the CSC docket for a declaratory ruling on a 4.99-megawatt BESS located at 100 Salmon Brook behind the urgent care facility.
The greatest concern with all BESS projects is fire. Lithium-ion batteries have a track record of igniting for various technical reasons. The primary ignition source is overheating of the battery core known as “thermal runaway”. Thermal runaway fires can result in toxic smoke plumes and even explosions. As documented in California, evacuations become of paramount importance. One source recommends that emergency response guidelines establish an evacuation ring of one-third of a mile in all directions. For full evacuation status, our local infrastructure must dramatically improve at a substantial cost.
Granby doesn’t have the number of first responders required to handle such an event nor public communications other than cell phones to warn of the immediate danger. Adding to the potential confusion, Key Capture Energy will not have personnel on site. They have stated that the facility will be monitored remotely by a third party. For the safety of firefighters, departments like New York City established procedures requiring an authorized company representative be on-site before any first responders are admitted to the property. How long would it take for a company representative to be on-site?
LAFD lacks the equipment and training to handle hazardous chemical fires. Granby firefighters are volunteers who do not have chemical certified HAZMAT safety suits or the required special breathing apparatus. Lithium-ion fires cannot be extinguished because ion contains a built-in oxygen supply. Based on literature and research, the prescribed method of fighting a utility-scale lithium-ion fire is to let it slowly burn out while keeping it cool with a water spray. This process can last as little as two days to an extended period. Aside from toxic smoke fumes, the water from fire hoses will accumulate in the storm basins and accumulate until the water and all toxic chemicals dump into the Salmon Brook wetlands. There is not a fire hydrant nearby. Unless one is installed, water will have to be transported. The Salmon Brook is a federally certified wild and scenic stream. In the event of a fire, who will pay for the environmental cleanup and damage but also the costs associated with any potential health needs of the firefighters and residents?
Operating BESS projects should be a major concern to residents of Granby and the Farmington Valley. Local town boards and commissions do not have the legal right to deny these projects. That authority has been delegated to the Connecticut Siting Council but that does not exclude you from contacting town and state officials to express your concerns.
Editor’s note: R. W. Maier is an electrical energy professional.